Java Utililty Methods Reflection Constructor Get

Constructor<T> constructor = null;
if (expectedTypes == null) {
    expectedTypes = EMPTY_CLASS_ARRAY;
try {
    constructor = clazz.getConstructor(expectedTypes);
} catch (NoSuchMethodException e) {
    Constructor[] constructors = clazz.getConstructors();
...

try {
    return cls.getConstructor(parameterClses);
} catch (NoSuchMethodException nsme) {
    StringBuffer sb = new StringBuffer();
    sb.append(cls.getName());
    for (Class<?> parameterCls : parameterClses) {
        sb.append(" ");
        sb.append(parameterCls.getName());
...

try {
    return cls.getConstructor(args);
} catch (NoSuchMethodException e) {
    throw new IllegalStateException(e);

Class<?>[] argsTypes = toClass(args);
return getConstructor(cls, argsTypes);

Constructor<?>[] constructors = instanceType.getConstructors();
for (Constructor<?> constructor : constructors) {
    if (constructor.getModifiers() == Modifier.PUBLIC) {
        return (Constructor<T>) constructor;
return null;

try {
    return targetClass.getConstructor(parameterTypes);
} catch (NoSuchMethodException ex) {
    throw new IllegalStateException(ex);

Constructor<T> constructor;
try {
    constructor = type.getDeclaredConstructor(parameterTypes);
} catch (NoSuchMethodException ex) {
    throw new IOException(ex);
} catch (SecurityException ex) {
    throw new IOException(ex);
return constructor;

try {
    return type.getConstructor(parameterTypes);
} catch (NoSuchMethodException e1) {
    try {
        return type.getDeclaredConstructor(parameterTypes);
    } catch (NoSuchMethodException e2) {
        throw e2;

if (parameterTypes.length == 0) {
    return theClass.getConstructor();
} else {
    for (final Constructor constructor : theClass.getDeclaredConstructors()) {
        final Class[] types = constructor.getParameterTypes();
        if (types.length != parameterTypes.length) {
            continue;
        if (types.length == parameterTypes.length && types.length == 0) {
            return constructor;
        boolean fits = true;
        for (int i = 0; i < types.length; i++) {
            if (!isAssignable(types[i], parameterTypes[i])) {
                fits = false;
                break;
        if (fits) {
            return constructor;
    throw new NoSuchMethodException(theClass.getCanonicalName() + argumentTypesToString(parameterTypes));

try {
    final Constructor<? extends E> c = clazz.getDeclaredConstructor(parameterTypes);
    return Optional.<Constructor<? extends E>>of(c);
} catch (final Exception e) {
    return Optional.<Constructor<? extends E>>empty();